This application proposes a training plan for Eric Geier, a predoctoral student at UCSD School of Medicine/Department of Biomedical Sciences studying under the mentorship of Dr. Kim Prisk. The group led by Dr. Prisk has recently developed a method of non-invasively mapping pulmonary specific ventilation (Specific Ventilation Imaging, SVI) using proton Magnetic Resonance Imaging (MRI). Mr. Geier plans to systematically streamline this technique in a rigorous optimization process, making it faster and less technically demanding so that it can be made accessible to other research centers. Long-term, this will enable multi- institution studies of large patient populations, the result of whichwill be new insights into the pathophysiology of lung disease. As a proof of concept, Mr. Geier plans to apply the streamlined MRI technique to characterize the spatial variability of bronchoconstriction during asthma attacks. The spatial distribution of ventilation defects in asthma has been shown to be patchy, but little is known about the spatial reproducibility of the patchiness from one attack to the next. This is primarily due to the fact that repeated measurements of regional ventilation distribution have been difficult to acquire. Is bronchoconstriction a spatially diffuse, temporal dynamic process or is it spatially-persistent and driven by underlying anatomical factors? The hypothesis is that chronic, moderate asthmatics will display a spatially-persistent pattern of ventilation defects during asthma attacks due to chronic inflammation and tissue remodeling, while healthy, normal individuals will show a spatially variable pattern of bronchoconstriction. This proposal will provide a framework in which Mr. Geier can develop his potential as a researcher. In addition to the technical and scientific skills he will learn from his mentor, Dr. Prisk, Mr. Geier will be given opportunities to interact ith a variety of expert collaborators. He will develop an understanding of pulmonary physiology and pathophysiology from interactions with Dr. Susan Hopkins and other faculty members in the UCSD Division of Physiology, a department that has been a world leader in pulmonary physiology for the last 40+ years. Under the supervision of Dr. Rebecca Theilmann, Mr. Geier will learn how MRI pulse sequences are designed and implemented. Mr. Geier will work closely with Dr. Rui Sa, one of the researchers who originally developed and published the MRI-based Specific Ventilation Imaging technique, for the entirety of the proposed project.